Folding knives are well known in the art and serve a variety of uses, with the primary purpose of the folding feature being to conceal the sharpened edge of the blade so that the knife may be safely carried without an additional cover or sheath. An additional purpose is to reduce the overall length of the knife for more convenient carrying.
Numerous designs of folding knives have been developed in the past, both of the locking and non-locking variety. The primary benefits of the simple, non-locking foldable knife are its simplicity and economy, since there is usually only one principal moving part, the blade. However, any inability to lock the blade in its extended position places serious limitations on the use of such a knife for purposes such as self defense and other demanding activities.
Locking foldable or retractable knives have taken many forms, including blades which slide out of the handle and lock, and pivoting blades which are released and locked by one or more mechanisms operated by the user. While such knives have broad utility and are available in many forms, they usually suffer from one or more of the following deficiencies: inability to accommodate a blade with more than one sharpened edge; inability to be opened or closed with either hand; awkward or unreliable operation of the blade locking mechanism; inability to be quickly and easily disassembled for maintenance or repair; and susceptibility to contaminants which could render the knife inoperable. Therefore, despite the long and continued development of folding knives capable of being positively locked in the open position, there still exists the need for a knife of economical construction which can satisfactorily overcome the aforementioned deficiencies of contemporary folding knives.